Detector for oscillating currents.



w. E. BEAKES. DETECTOR FOR OSCILLATING CURRENT'S. APPLICATION FILED MAY 9. I911.-

' 1,15%,1 mo Patehted Oct; 26', 1915;

' a eitizen of the United States, residing at Currents.

Y'To all whom it may concern:

* 1 all; STATES PATENT OFFICE.

WILLIAMN. Beams, or BRAIN-'1 ROCK, massacnusn'rrs, ASSIGNOR, BY MEsN-E Ass'IeN- MENTSy'lO' SAMUEL M. KINTNER, OF P nn'rno'ron roNiosoILLA'rIN cURRn rs.

'Be it known that I WILLIAM E. Brains,

Brant Rock, in the State of Massachusetts,

have invented certain new and useful Improvements in Detectors for vOscillating M invention relates more particularly to tact type, and comprises the discovery of a material having great I advantages for indi catingthe presence of oscillating'currents, together with the best means of assoc1at1ng I the "same with circuits.

. I have: illustrated the invention in thefac- .comp'anying drawing, in.which- Figure 1,is a diagram-.ofthe preferred method of employing 'thetreceiver; Fig. 2-isj .a central cross-section of a convenient form ing currents of very high employed in wireless telegraphy 's'ignallng. Some have attributed it to various crystals 1 ofmounting the detector; and Fig. -3 is a diagram showing an alternative'method of hooking the detector in the circuits.

telegraphy have been employed, of which the essential,

Various detectors -for wireless element-was a joint between two electrodes which has the ability, inspme way not now known,.to indicate the presence of oscillatfrequency such as thermoelectric action, and some have called .'theaction .rectifyingi? All that is.really known is that oscillating currentspassing.

'-' through a joint between certain electrodes,

v efi'e'ct'jpf a current which can operate an in-.' dicato rtfsuch as a telephone. .This occurs in makes its presence manifest by T giving the some cases in connection with a constantly flowing-local current through the joint, and

in some cases without this auxiliary current." I have discovered that such 'a joint between the materials ferro silicon andantimony has a very great advantage in being very steady, allowing a heavy pressure with perfeet contact, being immune from disarrangement by. static disturbances and not requiring delicate adjustment.

As illustrated in thedrawing ltprefer to use, in connection with the antenna circuit 4:, 5, 6, a secondary circuit consisting of the coil 7 of a transformer, the detector 8, 9,

' battery 10, telephone 11 and condensers 12 and 13, one of which, 13, should be-variable.

n Specification-of Letters Patent. Patgjmbgdl 110113.26, 1915. Applicationfile'd May 9, 1911, seriarNaezaors. a w I T'1SBURGH, PENNSYLVANIA, ANn EALSEY It will be understood that the battery is v with a variable potentiometer coil 14. The

oscillating current takes efi'ect at the detectorf8, 9, insuch a way as to vary the current in the telephone 11 in approximate proportion to the'energy of the received .waves on the antenna 4.

T The detector'as shown, comprises a metal cup 15 containing a ferro-silicon .block 8, which is in good contact; with a piece of antimony 9, adjustably held by a spring arm 18 and s'crew 19. Both these latter are I pivoted on a bolt 20 carried by-a pivoted arm 21 on a post '22, all the parts being mounted on a base 23 and provided with the usual binding post 24, 24. Thus the anti-'. mony point 9 may be moved to any part of the ferro-silicon block 8 and the pressure varied by the screw. 19 and spring 18. I find this instrument works'best with a vcomparatively heavy pressure between the electrodes l 8, 9;} the antimony block 9 having a blunt point and the ferro-silicon bein'g'in rough crystal form, Also I findthe connection as ln' practlcal use I have found this detector I to be'about as sensitive as the so-called perikon detector, and very free from disturbance and easy to adjust on account of the lent contact between the electrodes.

I Having thus described my invention and illustrated its use, what I- claim is:

1. A detector for wireless telegraphy comprising-a good contact joint between two other ferro sili'con.

. 2. A detector for wireless telegraphy conj Witnesses;

- ANDREW HEBG, J1 -CimsrG.

excel- 4 electrodes of which one isantimony and the n. BEAKES. 

